ID   B2MG_RAJEG              Reviewed;         111 AA.
AC   Q8AXA0;
DT   30-MAY-2003, integrated into UniProtKB/Swiss-Prot.
DT   01-MAR-2003, sequence version 1.
DT   25-MAY-2022, entry version 65.
DE   RecName: Full=Beta-2-microglobulin;
DE   Flags: Precursor;
GN   Name=b2m;
OS   Raja eglanteria (Clearnose skate).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Chondrichthyes;
OC   Elasmobranchii; Batoidea; Rajiformes; Rajidae; Raja.
OX   NCBI_TaxID=33514;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RX   PubMed=12415263; DOI=10.1038/ni849;
RA   Cannon J.P., Haire R.N., Litman G.W.;
RT   "Identification of diversified genes that contain immunoglobulin-like
RT   variable regions in a protochordate.";
RL   Nat. Immunol. 3:1200-1207(2002).
CC   -!- FUNCTION: Component of the class I major histocompatibility complex
CC       (MHC). Involved in the presentation of peptide antigens to the immune
CC       system (By similarity). {ECO:0000250}.
CC   -!- SUBUNIT: Heterodimer of an alpha chain and a beta chain. Beta-2-
CC       microglobulin is the beta-chain of major histocompatibility complex
CC       class I molecules (By similarity). {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000250}.
CC   -!- SIMILARITY: Belongs to the beta-2-microglobulin family. {ECO:0000305}.
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DR   EMBL; AF520476; AAN62852.1; -; mRNA.
DR   AlphaFoldDB; Q8AXA0; -.
DR   SMR; Q8AXA0; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0042612; C:MHC class I protein complex; IEA:UniProtKB-KW.
DR   GO; GO:0002474; P:antigen processing and presentation of peptide antigen via MHC class I; IEA:UniProtKB-KW.
DR   GO; GO:0006955; P:immune response; IEA:InterPro.
DR   Gene3D; 2.60.40.10; -; 1.
DR   InterPro; IPR015707; B2Microglobulin.
DR   InterPro; IPR007110; Ig-like_dom.
DR   InterPro; IPR036179; Ig-like_dom_sf.
DR   InterPro; IPR013783; Ig-like_fold.
DR   InterPro; IPR003597; Ig_C1-set.
DR   PANTHER; PTHR19944:SF62; PTHR19944:SF62; 1.
DR   Pfam; PF07654; C1-set; 1.
DR   SMART; SM00407; IGc1; 1.
DR   SUPFAM; SSF48726; SSF48726; 1.
DR   PROSITE; PS50835; IG_LIKE; 1.
PE   3: Inferred from homology;
KW   Immunity; Immunoglobulin domain; MHC I; Secreted; Signal.
FT   SIGNAL          1..17
FT                   /evidence="ECO:0000255"
FT   CHAIN           18..111
FT                   /note="Beta-2-microglobulin"
FT                   /id="PRO_0000018811"
FT   DOMAIN          20..111
FT                   /note="Ig-like C1-type"
SQ   SEQUENCE   111 AA;  12782 MW;  3E7B22BC6BEBB5EB CRC64;
     MRALILLSLG LLRVAVPSPP QVVVYTYKPV VHGEKNTLLC HAKEFNPPNV ELQLFEDGNV
     FSQANQTDLS FESNWKFKLT KFIELIPRED VEYSCHVMYM GKTSIYKLES F